Extensive polyculture (Spain)

Extensive fish culture in earthen ponds - “esteros” is a traditional activity in the salt-marshes area surrounding the Bay of Cadiz (S.W. Spain). This culture system started as a sub-activity associated to salt exploitation, but in the second half of 20th century became more relevant with the progressive abandon of salt-works. Some aspects such as progressive sedimentation and drying up of ponds, and low profitability are threatening the maintenance of the activity, and consequently the landscape.

These farms obtain a natural fry recruitment by an adequate management of water in-flow with the tides. The main fish species produced are mullets, seabass, seabream, sole and eel. The productivity in these traditionally extensive systems ranges between 150 and 500 kg/ha/year depending on areas and years. The main problems that may significantly reduce the production are impact of ichthyophagous birds and furtive fishing. The economic sustainability of this extensive culture system is strongly depending on the appropriate management and integral use of all resources, including the recovery of drained areas and transformation to extensive culture of the former crystallization ponds, and on product differentiation.

The main objective is to perform a comprehensive evaluation of the  possibilities of extensive fish culture areas, by comparing the production between ponds that have been working for many years and recent restored areas as well as to provide ‘added-value’ to extensive culture by the assessment of the supplemental recollection of invertebrates and eels.

Publications

D61 Extensive fish polyculture in earth ponds– esteros

D67 Scientific/Technical publication on extensive fish culture in earthen ponds – esteros